During the raid, which took place in the middle of the day, masked intruders reportedly tied up staff and stole computers before fleeing to the U.S. On Thursday, U.S. authorities arrested Christopher Ahn, a former U.S. Marine, in connection with the break-in. Ahn is a member of Free Joseon, a group dedicated to the overthrow of North Korean leader Kim Jong Un and his familial dynasty. Free Joseon reportedly claimed responsibility for the embassy raid in March. Free Joseon was trying to assist the U.S. government by turning over the stolen items, which the group claimed potentially had "enormous" intelligence value, per the Post.

The State Department said that the United States had nothing to do with the incident, despite initial reports out of Spain that the CIA was involved.